Boat speedometer



Sept. 2l, 1948. R. c. coLPAERT BOAT sPEEDoMETER Filed May 24, 1946 IfIvIII 0a erf www Patented Sept. 2l, 1948 fsf-rares fafrnnr N freier ,y y l, f`.,1449,59o 1 f BATISPEEDQMETER v 'Roger Colpaert, Detroiti'll/Iich. implication :Mayr-24, 1946; seria-ism; 612,126

,l l 4ffMy invention: Arelates ometer yforrwatercraft,` 2and` the prima-ry?'object of my inventionwis to f provide a novelwelectromechanicalzdeviceo this-.character wliichzis operatedibyv thepressureof thewateragainst aspringbalanced 'plunger' upont `forwardw `motion or `the craft, andfiscombinedwith Aelectricalv means ifor Calibratingfztheyamountr'of movement of the plunger and showing the results in terms of miles per hour. i

.l'lnlother important object of my invention is to provide a simple and reliable speedometer 'of small size and compact design which is relatively inexpensive-and is easily installed.

Other-important objects and advantages of. my invention will be apparent from the followingldescriptionand the accompanying drawings? wherein- `for purposes of illustrationlonly, a preferred embodiment is set forth in detail.

In the drawings:

Figure 1 is a general Vertical longitudinal centrai section taken through Figure 2 on the `line l-v-I, and .showing installation thereoflfin the bottom of aboat. p l; .i

Y Figure 2,is a horizontal.'y section. takenifon-the line 2 2 of Figure 1,

Figure 3 is a to-p plan view of the rheostat with the cover removed.

Figure 4 is a top plan View of the electrical indicator or speedometer dial and mechanism.

Figure 5 is a wiring diagram of the electrical connections.

Referring to the drawings in detail, the numeral 6 generally designates the body of the water speedometer, which comprises the horizontal cigar-shaped lower part I composed oi the lower section 8 and the upper section 9, joined along the horizontal line Ill, and preferably formed of bronze castings. The upper section 9 has rising centrally therefrom the elongated thin section strut Il, which includes at its upper end a forwardly and rearwardly enlarged portion I2 having a at top I3 for engaging a gasket I4 pressed against the bottom plate I5 of a boat (not shown) Rising from the strut portion I2 intermediate its ends is a tubular portion I6 which has on its upper end the speedometer dial mechanism, which is generally designated II, hereinafter described in detail.

The tubular part I 6 is threaded at I8 above the boat bottom I5 for a nut I9 which is to be threaded downwardly thereon against a washer which in turn presses on a gasket or packing ring 2i engaging the upper side of the boat bottom I5 geminis." (c1. 'vs 186) around the hole 22 which passes-.i-,saidftubular portion l-I, f whereby s the deviceeis-i securely-finstalledfin watch-tight manner.

1 .TheborefZS/of theltubularportionwl a continues i l downwardly'threugh rthe.- strut;"portion,` :1I Iz.ancl

upper body sectionJ Bittoyopeminto thetppoh a longitudinal elongated generally rectangular chamber 24 formedrfin theY bottom of said upper sectionfand closedfomthe lowerv side by'tlieitopof thelower 'section 8. Alignedslide bores-25 and 26 are formed through the frontfand ,rear'ends-otthe upper bodysection 9 which'open intolcorrespond-4 ingendsl-ofithechamber.24. l I l n Ahorizontal-vrectangularframe E'Lhaving' rack teeth fail alongtone side-` thereof is located in the chamber 24y and has attached toits oppositefends the rods. l 29 and 3B, respectively, which.; slide- .in the bores --25` and -2-,respectively. Theirearcencl of thewbore:` 2liy is :closechley-v az-threaded plug 3l w-hichl-actstas an abutment? for. the adjacent-.end oi ahelical. expanding nsprl-ng 32 .positioned inthe bore 3 i with its oppositesend.engagingithe:slide rod 3Q. The ifront slide ,rod zii-has a iiat pressure head-Saponztheforward end. l l

p i Meshedswith r.thesrackiteeth` Zanoni-the .frame 27 is a pinion 34 on a rotary shaft 35 pivoted at its lower end in a socket 36 formed in the lower body section 8 and journaled at its upper end in I an opening 31 in a plate 38.

The said plate 38 forms the bottom of a circular pan-shaped rheostat mechanism casing 39 which has an insulated rheostat resistance element lil arranged around the inner side of its side wall, as indicated in Figure 3. A spring-pressed wiper Contact lll is Xedly mounted o-n the upper end of the shaft 35 with its contact or brush 4Z engaging the resistance element 4G. A casing collar 3S iits on the top of the tubular portion I3 and is secured by screws 4U. I

It is obvious from the foregoing that the balancing spring 32 keeps the forward rod 219 in its .forwardmost position when the boat is not moving forward or is not standing in a rearwardly iiowing stream, and that, as the boat moves forward the pressure of the water on the head 33 will push the rod 29 rearwardly an amount corresponding to the magnitude of the water pressure and that this operates through the rack teeth 28 and pinion 34 to turn the shaft 35 and change the position of the brush 42 on the rheostat element 30, thereby correspondingly varying the resistance of any electrical circuit in which the rheostat may be incorporated.

This variation in electrical resistance is here used to Vary the magnetization of a solenoid coil 43 having a core 44 pivoted at one end at 45 to an arm 46 on a sector gear 41 pivotally supported at 48 in a speedometer dial casing 49. The sector gear 41 is meshed with a pinion 50 including a needle or pointer 5l pivoted on the casing 49, with a contractible spring -58 stretched between a part of said casing and one side of the sector gear 41 to initially position the pointer 5I at zero on the miles-per-hour concentric dial 53, and return it to zero after operation around the dial.

It is clear that the amount of energization of the solenoid coil 43 is determined by the travel of the rheostat contact 42 on the rheostat element 49 away from its starting position in response to the water pressure on the head 33, and that the amount of energization or magnetization of the solenoid coil determines the position of the pointer 5I relative to the dial 53 to accurately show the forward rate of speed of the boat in still water.

The speedometer dial mechanism casing I1 may be mounted on any suitable place in the boat and have the necessary wires 54 and 55 (see Fig. 5) led thereto, with a hand switch 56 and a battery 51 connected in the wire 54.

I claim:

1. A speedometer for a boat having a bottom panel comprising a streamlined body adapted to' be positioned in the water beneath said panel in fore and aft manner and having a reduced portion adapted to rise'through and be sealed in an opening formed in said panel into the interior of the boat, a forwardly spring-pressed plunger working horizontally in said body, said plunger having a water pressure head against which the water presses on forward motion of the boat to move said plunger rearwardly an amount corresponding to the forward speed of the boat, a

vertical rotary shaft extending through said re- 40 duced portion and into said body, means operatively connecting said shaft and plunger to turn said shaft in opposite directions in accordance with the position and movement of said plunger, a lateral rheostat contact fixed on the upper part of said shaft, a circular rheostat resistance element supported on the upper part of said reduced portion for engagement by said contact.

2. A speedometer for a boatvhaving a bottom panel comprising a streamlined body adapted to be positioned in the water beneath said panel in fore and aft manner and having a reduced portion adapted to rise through and be sealed in an opening formed in said panel into the interior ofthe boat, a forwardly spring-pressed plunger working horizontally in said body, said plunger having a water pressure head against which the water presses on forward motion of the boat to move said plunger rearwardly an amount correspondingvto the forward speed of the boat, a vertical rotary shaft extending through said reduced portion and into said body, means operaatively connecting said shaft and plunger to turn REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 353,649 Waddell Nov. 3, 1886 613,899 Eldridge Nov. 8, 1898 1,745,782 Cheney Feb. 4, 1930 2,082,539 Fischer June 1, 1937 FOREIGN PATENTS Number Country Date 140,741 Germany June 13, 1902 184,740 France July 12, 1887 371,352A Great Braam .Jan. 19, 1931 

